Friday, August 12, 2011

Old glass: Asahi/Pentax SMC & Super-Takumar 50/1.4

Many of you know that I like old things, and that includes camera lenses. I love using inexpensive, old, manual-focus glass on my new DSLR body. I promised earlier to take some time now and then to talk about some of my older equipment, and this is the first installment. Today, I highlight two of them: my trusty Asahi (Pentax) Super-Takumar 50mm f/1.4 lens (built in 1967) and it's younger brother, the SMC Takumar 50/1.4 (built in 1974). Although I have quite a selection of "fast fifty" lenses on my shelf, the Super-Tak is the one I grab most frequently for low light and portrait shooting.
The Asahi Optical Company, marketed as Pentax in most of the world and, for a time, as Honeywell in the United States, was one of the premier camera manufacturers back in the 1960's and 70's. Pentax popularized the M42 lens mount (a 42mm threaded mount first used by Zeiss in 1949), to the point where many people refer to M42 as the "Pentax screw mount." M42 was used by many manufacturers back in the day, which makes those lenses and bodies very easy to come by on the used market.

1967 Super-Tak and 1974 SMC Tak

During that time, their Takumar series of lenses were some of the highest quality glass available. There are several generations of Takumars, as the line spans several decades. The "Super-Takumar," which appeared in 1964, was the first to have decent lens coatings, and is hence the earliest model which is still popular with manual focus enthusiasts as anything more than a curiosity. The "Super-Multi-Coated Takumar" (aka "S-M-C Takumar," with hyphens) replaced it in 1971, and as you might guess, possessed a more advanced multiple-coated lens surface to improve contrast and reduce flare. The S-M-C Tak used essentially the same exterior body and metal focusing ring as the Super-Tak. The "SMC Takumar" (no hyphens) appeared in 1973, overlapping the S-M-C Tak for several years. The SMC Tak had similar optics to the S-M-C, but a different body with a rubber focusing ring. The SMC and S-M-C also had an improved 8-blade aperture (vs the Super's 6 blades). Although the SMC is the most sought after of the 1.4/50 Taks, I prefer the aesthetics of the Super's and S-M-C's metal focusing ring.

1967 Super-Tak 50/1.4

1974 SMC Tak 50/1.4

Pentax gradually replaced the M42 mount with its proprietary K-mount (or PK-mount) from 1975-1980. Though probably unrelated, the reputation of their Takumar lenses also diminished significantly after 1980. My 1984 copy of a Takumar (Bayonet) 135mm f/2.5 lens supports this opinion, unfortunately.

Super 50/1.4, Super 55/1.8, and SMC 50/1.4

My Super-Tak 50/1.4 was one of the first manual lenses I purchased (four months after buying my first DSLR), and the only one I've obtained from eBay. At $35, it was one of the more expensive lenses I've purchased, but that's to be expected from eBay. I find much better deals at pawn shops and estate sales. Fast (f/2 and wider) 50mm lenses came standard with virtually every 35mm camera made for several decades, so there are a billion of them out there on the used market. EBay pretty much defines the going street price for them. Most Pentax Spotmatic bodies came with a 55/1.8 lens, which is a wee bit smaller and lighter due to the smaller aperture. Still, the 50/1.4 isn't exactly rare, and is still easy to find today.

So, about this lens. It contains 7 optical elements (pieces of glass) arranged in 6 groups. The aperture ranges from f/1.4 to f/16. Minimum focusing distance is 0.45 meters (18") from your sensor, which means about 14" from the front of the lens. It takes 49mm screw-on filters, which is a very common size for that era. All of the above specs are shared with the S-M-C and SMC versions. The Super-Tak weighs in at 230g (8.1 oz), which is lighter than either the S-M-C (252g) or SMC (265g). That's almost twice as heavy as Canon's modern 50/1.8 (130g), which is known as the "plastic fantastic" for good reason, but lighter than Canon's modern 50/1.4 (290g). The Super-Tak 50/1.4 was made from 1964-1971; the S-M-C from 1971-72, and the SMC from 1973-75. My 1967 Super-Tak is the oldest lens I own that can be used on my DSLR's.

Six aperture blades at f/16

Eight aperture blades at f/16

Wide open at f/1.4

The entire Super/S-M-C/SMC line has a great reputation among manual lens enthusiasts. They're pretty sharp wide open, but when stopped down to f/4 or farther, they're wicked sharp. Other than autofocus, no significant advancements have been made to 50mm primes since the mid-1970's, so optically, the SMC Takumar still represents the state of the art for this type of lens. This lens that I bought for $35 is every bit as sharp as the modern Canon 50/1.4 that sells for $400. For my purposes, autofocus isn't worth paying ten times as much for the same lens. Photos shot through these 1960's lenses (I've got a few from that decade) each have a different look about them that's quite different from the sanitized look of modern, auto-focus zooms. It's hard to put your finger on just how to describe it, but you can see it if you look closely at the three photos below. I like it, personally.

Super-Tak 50/1.4 @ f/2.8

SMC Tak 50/1.4 @ f/2.8

Sigma 17-70/2.8-4.5 @ f/4

This lens is my go-to portrait lens due in part to its focal length (50mm on a Canon APS-C equates to 80mm on a full-frame 35mm body) and in part to its sharpness at relatively wide apertures (f/2.8 to f/4). The one drawback to using my Super-Tak wide open is that out of focus highlights, which appear as blurred circles, have a harder-edged ring around them. It's not bad, but it's more noticeable than my Tamron 90/2.5 (52B) macro lens. It's a fun effect sometimes, but other times I wish the bokeh was just a bit more creamy.

Super-Tak 50/1.4 on Canon 7D

Using this lens is really a joy. It's very small and light, almost to the point where it looks funny attached to my huge Canon 7D with its vertical grip. The focusing ring turns very smoothly, and it has a wide enough spread (120 degrees) that fine tuning focus at f/1.4 is very precise. The wide f/1.4 aperture is wonderful to use in low light. F/1.4 is 2/3 stops faster than f/1.8, which increases your shutter speed or decreases your ISO by 60% compared to Canon's modern 50/1.8 lens. The wide aperture is also great when you want the creative effect that a shallow depth of field (DOF) provides. In a portrait at minimum distance, if the eyes are in focus, the nose and ears will be quite out of focus.

Alas, with that shallow DOF comes some difficulty in focusing accurately. It doesn't take much of a change to make your desired focal point unacceptably blurry. There are two ways around this, both of which I employ when possible. Most current DSLR bodies have a LiveView feature that allows you to see on the LCD exactly what the sensor sees. By zooming in 5x or 10x on a high contrast edge in LiveView, it's easy to tell when that edge is in focus. Unfortunately, 10x can jump around a lot when hand held, so this really works best on a tripod. This method is also rather slow, so it only works on static subjects.

Split image circle with a microprism ring

A more general purpose option is to get an aftermarket focusing screen that includes a split image circle with a microprism ring, just like the ones that came in most manual focus camera bodies. Even though today's viewfinders are typically smaller and darker than those in the older bodies, these focusing aids can make it much easier to judge accurate focus rather quickly through the viewfinder. I'm quite happy with the screens I've gotten from KatzEye and FocusingScreen.com.

As with most lenses (except Olympus and several older lenses), the aperture ring is right at the base of the lens, so those with large fingers may have some trouble turning the ring quickly and accurately. The ring turns in half stop increments, so it's easy to count the number of clicks when adjusting the aperture with your eye up to the viewfinder. Due to the half or whole stop increments in most manual lenses, I've also set my 7D body to adjust its shutter & aperture settings in half stop increments rather than the third stop increments that it came with. Look through your custom functions for this option (on the 7D, it's CF I-1).

Quick focusing and metering is made easier by the lens' auto/manual switch. On a native M42 body like the Pentax Spotmatic, this switch controls whether the camera is allowed to stop down the lens aperture (auto), or whether the lens' aperture ring sets the aperture all the time. On non-native bodies, the auto setting opens the aperture to f/1.4 regardless of what the ring is set to. This allows you to meter at, say, f/8 with the switch in manual mode, then quickly flip the switch to auto, focus accurately at f/1.4, and the flip it back to manual mode to take your shot at f/8. It's a handy feature to have when shooting mobile subjects.

The automatic setting -- which is the only setting that some M42 lenses have -- is accomplished by a small stop down pin that sticks out the back of the lens mount. When a native camera wants to close down the aperture to the setting on the ring (as it would just as the shutter button was pressed), a lever inside the camera body would press this pin into the lens. I mention this because there are two types of M42-EOS mounting adapters. One type has a little flange inside the M42 threads that will automatically depress this pin whenever the lens is attached to the adapter. The other type has no such flange. When using a lens like the Super-Tak 50/1.4 which has an auto/manual switch, it's best to have an adapter without a flange so that you can flip the aperture back and forth as described above. However, many M42 lenses lack this auto/manual switch (possessing only an automatic mode), so those lenses require a flange in order to make the lens stop down to the specified setting all the time. Without the flange, such lenses could only be used wide open.

Adapter wih AF-confirm chip

Speaking of adapters, M42 lenses typically provide the lowest cost of entry to the world of manual focus because the adapters are so simple to machine (often costing $10 or less) and because the lenses themselves are so plentiful. Takumars are a great place to get your feet wet. Most of my posts talk about use on a Canon EOS body, but you can also use these M42 lenses on modern Pentax bodies with an M42-PK adapter, or on Olympus 4/3 DSLR's, or on Olympus or Panasonic micro-4/3 bodies, or on Sigma DSLR's by using different adapters.

Another interesting note about these Takumar 50/1.4 lenses and the related 35/2 lenses -- but apparently not the 55/1.8 or any other focal lengths -- is that the rear glass element often contained thorium, a radioactive element. The levels of radioactivity are low enough that you'd never notice. In fact, you'll absorb more radioactivity by eating a banana. However, thorium does cause the rear element to yellow over time if the lens isn't used regularly, which introduces a yellow cast to all your photos. Don't confuse this yellowing with the yellow-looking coating on the Super-Taks. To see if your lens is yellowed, look through it at a brightly lit, neutral grey surface. There's much disagreement regarding exactly which other lenses are affected and why the yellowing occurs, but we all know it happens on these 50/1.4's. To fix this, simply set the lens on a window sill in bright, direct sunlight for a few weeks. A UV plant grow light will work in a pinch if you happen to be wintering at the South Pole.

Infinity on left, minimum focus on right

There is one point to make about mounting this particular lens on EOS bodies. The lens is designed in such a way that the rear lens element extends back into the camera body when the lens is focused to infinity. On crop sensors, this isn't a problem. However, on full frame cameras like the Canon 5D or 1Ds, or on 35mm film cameras, the larger reflex mirror will actually come into contact with the rear lens element at infinity. If you want to use any of the Takumar 50/1.4 lenses (or a small variety of other lenses that have this issue) on a full frame camera, you have two options: 1) never focus the lens to infinity so that the rear element stays a safe distance from your mirror, or 2) shave a small arc out of the bottom of your reflex mirror so that the mirror will clear the rear element as it flips up with each exposure. The latter really isn't as big a deal as you might think, but it is a consideration. In fact, it was a major consideration for me when I decided to buy my latest 7D body instead of a 5DmkII.

SMC Takumar 50/1.4, sans fungus

Any time you're talking about 40-year-old lenses, there's the possibility that you'll find one with rattling innards, stiff aperture rings, or fungus on the glass. Most of these maladies can be remedied by disassembling the lens and going over it with rubbing alcohol and fresh lubricant. The nice thing about this era of prime lenses is that they're quite a bit easier to work on than modern lenses. Even without instructions, if you're rather handy, you can tear down, clean, and reassemble one of these little beauties in just a couple hours. I had to do this to the SMC Takumar that I bought for just $17 because it had a bit of fungus inside. I was able to breath new life into that lens, although it's still not as sharp wide open as it ought to be.

Well, this is probably enough of an introduction to one of my favorite lenses and its family. I hope it will inspire some of you to experiment with this great old glass. If you want to take some time to learn more about how to use older, manual lenses on new, digital SLR bodies, check out my introductory post on the subject, or my Yashica 75-150/4 article, or my Tamron 90/2.5 article. As always, if you have any questions or comments about my Super-Tak 50/1.4 or anything else, please leave a comment below.

praktinafan, since I haven't tried to do this myself, I can't say for sure exactly where on the lens the mirror hits. I've got an EOS 35mm film camera that I care little about; I'll try to remember to test it out and report back what I find. The mirror should be in the same place on a 5D.

No, all of these Takumar lenses have straight-edged aperture blades which form traditional hexagons or octagons when stopped down. I can't imagine very many people would want their out of focus highlights to look like ninja stars. I've never seen a lens that creates this effect.

Oh, OK. I see what you mean. When you said "ninja star," I assumed you meant something with very pronounced points between each aperture blade, as if the blades were rounded outward.

The small little tips in your example photo are just where the rounded tip of each blade starts to disappear behind the adjacent blade. if the blades had been a couple mm longer, this wouldn't happen. I just checked all of my fast lenses (f/2.8 or wider), and you can see from the list that this is a very common malady. I don't think you'll be able to avoid it just by getting a different version Takumar.

I have two copies of that SMC Tak 50/1.4, and both of them do exhibit the same small points at f/2. The effect disappears by f/2.8 in both of my copies.

My Super-Tak 55/1.8 has it just as bad as the SMC Tak 50/1.4.

My Super-Tak 50/1.4 has it, but it's barely perceptible at f/2 and gone by f/2.8.

My SMC Pentax-M 50/2 has it at f/2.8, but it's gone by f/4.

My SMC Pentax-M 35/2.8 has it at f/4, but it's gone by f/5.6.

My Nikkor-S 50/1.4 NKJ has it at f/2.8, but it's gone by f/4.

My Micro-Nikkor 55/2.8 just barely has it at f/4, but it's gone at f/5.6.

My Nikkor 135/2.8 is free from it.

My Olympus F.Zuiko 50/1.8 has it at f/2.8, but it's gone by f/4.

My Vivitar 24/2 has it at f/2.8, but it's gone by f/4. My Vivitar 28/2.5 is free from it.

My Tamron 52B 90/2.5 has it for several stops, not disappearing until f/5.6.

My Yashica DSB 135/2.8 has it at f/4, but not f/5.6. My Yashica ML 50/2 is free from it.

Thanks for this great article. As a newbie I really appreciated it. I've learnt alot about the lens i've just purchased for my EOS 650D. But I have a question about the different versions since my copy has another pin on the backside which obviously prevents the a/m-switch to switch back from auto to manual. Can anyone give me an advise to make this lens work on my EOS (apart from the flangeless takumar adapter) ? Thanks in advance! Cheers Martin

This second pin is visible on the far left side in the second-to-last photo above. It prevents switching from auto to manual mode unless the lens is actually mounted to a camera (or in our case, to an adapter). I have no idea why it's there.

Because this pin is located on the mating flange outboard of the screw threads, you don't need a special adapter; any adapter or camera body that screws onto this lens will depress that pin for you.

Hi Ben,thanks for your reply! I was confused because at first I only tried the lens on the Pentax Sportmatic F it came with. Mounted on this camera the a/m switch cannot be flipped back from automatic to manual due to a groove in the Sportmatic F body. But this is intended by the manunfacturer as the later camera bodies were designed for open aperture metering. I haven't realized this until now. So I had thought a regular adapter wouldn't push that little pin either. Cheers Martin

Interesting. I've got one or two Spotmatics, but I guess I've never seen an F. I still don't understand why that pin exists, or why Pentax would intentionally bypass it on the F. If the user wants manual control, let them have it. That's what the A/M switch is for.

I've never seen an adapter that had a groove like that & wouldn't depress that pin, but that's no guarantee that they don't exist. Consistency and quality control are not hallmarks of east Asian eBay sellers, unfortunately.

I purchased the Super-Multi-Coated 50mm f1.4 and can confirm that it does collide with the 6D mirror.

Apparently some of the other varieties, Super Tak, SMC are fine with the 6D. Wish I would have know that. Especially since I've already begun to file the back rim around the glass down in hopes it clears. Either way I'll keep it for Fuji X later on.

Gleighton, for a Super-Tak 50/1.4, which has an auto/manual pin on the back, you want to get an adapter WITHOUT a flange. For lenses that lack this auto/manual pin, you'll need an adapter WITH a flange. This is discussed about two thirds of the way down in the above article. Any of the adapters at the following link should work, just be careful about whether or not they have a flange:M42-EOS on Amazon

What is your opinion between these two lenses (super tak vs smc tak), are they very close in quality/performance? Do you prefer the older one? I am going to buy one of those and would aprecciate an opinion.

Sorry for the delayed response. I prefer the feel and the external appearance of the Super's metal focusing ring over the SMC's rubber ring.

The SMC has 8 aperture blades vs the Super's 6, so that's an advantage when you're shooting out of focus highlights when not wide open. With the naked eye, I can't tell a difference between the sharpness of the two.

I think the best of both worlds would be the Super-Multi-Coated Takumar (often abbreviated "S-M-C" with hyphens). It looks like the Super externally, but has 8 aperture blades. It was manufactured in between the Super and SMC, but only for a brief time.